Characterization of the Composition and Immunoregulatory Activity of Wheat Cell Culture-Derived Polysaccharides

Plant polysaccharides can exert immunomodulatory activities. In this study we provided chemical characterization of wheat cell culture-derived polysaccharides (WCCPS) and assessed their capacity to modulate inflammatory responses in mouse macrophages. The total sample (T-010) contained arabinogalactans, arabinans, glucans and xyloglucans. Fractionation by anion-exchange chromatography rendered a bound acidic fraction (B-010) and an unbound neutral fraction (UB-010). The B-010 fraction was enriched in arabinogalactans and arabinans, with some galactans, homogalacturonans, and arabinoxylans. The neutral UB-010 fraction was composed of glucans and xyloglucans. None of the WCCPS preparations triggered cytokine production on their own, but each potentiated different macrophage responses to bacterial lipopolysaccharide (LPS). The total WCCPS in T-010 increased LPS-induced tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 secretion, whereas the acidic arabinogalactan-rich fraction B-010 boosted IL-6 release and selectively upregulated nitric oxide synthase 2 (Nos2) and cholesterol 25-hydroxylase (Ch25h) expression in response to LPS. In contrast, the neutral UB-010 fraction enhanced IL-6 levels and induced Nos2 expression without altering Ch25h expression. These results suggest that WCCPS can modulate distinct aspects of the inflammatory response, with their effects shaped by their composition and structural features. Future research will focus on elucidating the molecular mechanisms underlying the immunomodulatory activity of WCCPS.